An experimental study on crack closure induced by laser peening in pre-cracked aluminum alloy 2024-T351 and fatigue life extension

2020 ◽  
Vol 130 ◽  
pp. 105232 ◽  
Author(s):  
Yongxiang Hu ◽  
Han Cheng ◽  
Jianhua Yu ◽  
Zhenqiang Yao
Keyword(s):  
Experimental Study ◽  
Aluminum Alloy ◽  
Fatigue Life ◽  
Crack Closure ◽  
Life Extension ◽  
Laser Peening ◽  
Aluminum Alloy 2024

scholarly journals Numerical and Experimental Study on Fatigue Life Extension of U-rib Steel Structure by Hammer Peening

2017 ◽  
Vol 35 (2) ◽  
pp. 169s-172s ◽  
Author(s):  
Seiichiro Tsutsumi ◽  
Ryota Nagao ◽  
Riccardo Fincato ◽  
Toshiyuki Ishikawa ◽  
Risa Matsumoto
Keyword(s):  
Experimental Study ◽  
Fatigue Life ◽  
Steel Structure ◽  
Life Extension ◽  
Hammer Peening

scholarly journals IMPROVEMENT OF FATIGUE LIFE OF A HOLED SPECIMEN OF ALUMINUM-ALLOY 2024-T3 BY INDENTATION AND HOLE EXPANSION

2012 ◽  
Vol 06 ◽  
pp. 336-342 ◽  
Author(s):  
MD. SHAFIUL FERDOUS ◽  
CHOBIN MAKABE ◽  
TATSUJIRO MIYAZAKI ◽  
NOBUSUKE HATTORI
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Crack Growth ◽  
Testing Machine ◽  
Fatigue Tests ◽  
Growth Behavior ◽  
Crack Growth Behavior ◽  
Local Plastic ◽  
Aluminum Alloy 2024 ◽  
Pull Tests

A method of improving the fatigue life and crack growth behavior of a center holed specimen was investigated. Local plastic deformation was applied around the hole by indentation to achieve the purpose. A series of fatigue tests was conducted on aluminum-alloy 2024-T3. Push-pull tests were performed under a stress ratio of R= -1 and a frequency of 10Hz. The observations of the crack initiation and growth were performed with a microscope, and hardness around the hole was measured by Vickers hardness testing machine. In the present study, the longest fatigue life was observed in the case of an indentation specimen with the highest load. The indentation was performed on both sides of the hole edges. The crack growth rate was decreased by indentation or expansion of the material around the hole. From the experimental results, it is found that the fatigue life and crack growth behavior of a holed or notched specimen can be improved by a simple technical method that is related to the local plastic working.

Transportable Laser Peening System for Field Applications to Improve Fatigue and SCC Resistance of Offshore Components and Structures

2006 ◽  
Author(s):  
Lloyd A. Hackel ◽  
C. Brent Dane ◽  
Fritz Harris ◽  
Jon Rankin ◽  
Chanh Truong
Keyword(s):  
Fatigue Life ◽  
Stress Corrosion Cracking ◽  
Life Extension ◽  
Laser Peening ◽  
Large Structures ◽  
Aerospace Alloys ◽  
Titanium Aluminum ◽  
Medium Strength ◽  
Exploration And Production ◽  
Improve Fatigue

Laser peening technology has matured into a fully qualified production process that is now in routine and reliable use for a range of aerospace alloys. The technology is capable of extending the fatigue life and stress corrosion cracking life of components, and will enable designers to consider higher stress levels in life limited designs. Applications under development for steels include high and medium strength steels used in off shore oil exploration and production, titanium, aluminum and even ceramics and plastics as well as life extension of steel and aluminum welds. Fixed systems to treat components and transportable systems capable of field operations are available with a moveable beam that allows peening directly as needed on large structures.

scholarly journals The Effect of Laser Peening without Coating on the Fatigue of a 6082-T6 Aluminum Alloy with a Curved Notch

Metals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 728 ◽  
Author(s):  
Enrico Troiani ◽  
Nicola Zavatta
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Residual Stresses ◽  
Fatigue Behavior ◽  
Surface Hardness ◽  
Element Model ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Laser Peening ◽  
Laser Peening Without Coating

Laser shock peening has established itself as an effective surface treatment to enhance the fatigue properties of metallic materials. Although a number of works have dealt with the formation of residual stresses, and their consequent effects on the fatigue behavior, the influence of material geometry on the peening process has not been widely addressed. In this paper, Laser Peening without Coating (LPwC) is applied at the surface of a notch in specimens made of a 6082-T6 aluminum alloy. The treated specimens are tested by three-point bending fatigue tests, and their fatigue life is compared to that of untreated samples with an identical geometry. The fatigue life of the treated specimens is found to be 1.7 to 3.3 times longer. Brinell hardness measurements evidence an increase in the surface hardness of about 50%, following the treatment. The material response to peening is modelled by a finite element model, and the compressive residual stresses are computed accordingly. Stresses as high as −210 MPa are present at the notch. The ratio between the notch curvature and the laser spot radius is proposed as a parameter to evaluate the influence of the notch.

scholarly journals Effect of Electromagnetic Treatment on Fatigue Resistance of 2011 Aluminum Alloy

2016 ◽  
Vol 07 (03) ◽  
pp. 1650004 ◽  
Author(s):  
M. A. Mohin ◽  
H. Toofanny ◽  
A. Babutskyi ◽  
A. Lewis ◽  
Y. G. Xu
Keyword(s):  
Crystal Structure ◽  
Experimental Study ◽  
Electromagnetic Field ◽  
Aluminum Alloy ◽  
Fatigue Resistance ◽  
Life Extension ◽  
Beneficial Effects ◽  
Electromagnetic Treatment ◽  
Engineering Alloys ◽  
Pulsed Electromagnetic

Beneficial effects of the electromagnetic treatment on fatigue resistance were reported on several engineering alloys. These could be linked to the dislocation activity and the rearrangement of the crystal structure of the material under the electromagnetic field (EMF), resulting in delayed crack initiation. This paper presents an experimental study on the effect of pulsed electromagnetic treatment on the fatigue resistance of 2011 aluminum alloy. Circular cantilever specimens with loads at their ends were tested on rotating fatigue machine SM1090. Fatigue lives of treated and untreated specimens were analyzed and compared systematically. It has been found that the effect of the pulsed electromagnetic treatment on the fatigue resistance is dependent on the intensity of the pulsed EMF and the number of the treatment applied. Clear beneficial effect of the pulsed electromagnetic treatment on the fatigue resistance of the aluminum alloys has been observed, demonstrating a potential new technique to industries for fatigue life extension.

SEM study of humid air effect on fatigue of aluminum alloy 2024-T351

1989 ◽  
Vol 47 ◽  
pp. 298-299
Author(s):  
M. T. Jahn ◽  
H. C. Voris
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Stress Level ◽  
High Strength ◽  
Humid Air ◽  
Humid Environment ◽  
Sem Study ◽  
Aluminum Alloy 2024 ◽  
High Strength Aluminum Alloys ◽  
Air Effect

There is general agreement that the fatigue life of high strength aluminum alloys is reduced in humid environment. However, there are also data supporting the theory that humidity plays an insignificant role in the reduction of the fatigue life of aluminum alloy 2024-T351. In this study we examined the effects of stress level and water vapor density on the fatigue life of aluminum alloy 2024-T351 using scanning electron microscope (SEM). SEM evidence of the deleterious effect of humid air on the fatigue life of specimens cycled at intermediate stress level was presented. Discrepancies between this study and others were explained.Commercial aluminum alloy 2024-T35l (4.40Cu-1.45Mg-0.70Mn-0.23 Fe-0.15Si-0.13Zn) extruded bars were fatigue tested in reversed bending. The cycling was conducted in an environmentally controlled chamber. Ten specimens were machined for each fatigue stress level of 248, 276, 290, 317 and 359 MPa. Five specimens fran each stress level were cycled in desicated air at a relative humidity less than 45%.

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